There have been known vehicle seatbelt apparatus of the type wherein when a vehicle passenger or occupant gets off or is going to get off, a seat belt is securely retracted to thereby prevent the seat belt from being caught by a projection in a passenger compartment or by a door of an automobile. By thus retracting the seat belt in conjunction with the action of the vehicle occupant, the seatbelt apparatus is able to enhance the comfort and convenience of vehicle occupants.
A typical example of such comfort vehicle seatbelt apparatus is disclosed in Japanese Patent Laid-open Publication (JP-A) No. 2001-163186, corresponding to U.S. Patent Published Application No. 2001/0004030 A1. In the disclosed vehicle seatbelt apparatus, when a buckle switch detects disengagement of a buckle and a tongue plate of a seat belt, the seat belt is retracted through a motor. In addition, the seat belt is re-retracted under a certain condition as detailed below.
As shown in FIG. 6 hereof, the vehicle seatbelt apparatus 200 described in JP 2001-163186 A (corresponding to US 2001/0004030 A1) is arranged such that when a buckle switch 201 detects disengagement of the buckle and the tang plate (neither shown) of a seat belt 202, a seat belt controller 207 retracts the seat belt 202 through a motor 206. In addition, when an occupant detecting device 203 detects that no occupant is present in the automobile, when a door switch 204 detects that a door is open, and when an engine key switch 205 detects that an engine key is pulled out or is in an off state, the seatbelt controller 207 operates the motor 206 to re-retract the seat belt 202. By thus performing retracting operation two times, the seat belt 202 can be positively retracted into a predetermined storage position.
However, the prior vehicle seatbelt apparatus 200 has a problem that when the seat belt 202 is detached from the vehicle occupant during engine cranking operation where a power supply voltage supplied via an ignition switch (which is closed when the engine key switch 205 is turned to start up the engine) to the seatbelt controller 207 fluctuates largely, a belt take-up or retracting operation performed by way of rotation of the motor 206 becomes sluggish or lacks smoothness, causing discomfort and inconvenience to the vehicle occupant.